1. Technical Field
The present disclosure relates to light sources and, more particularly, to a diffusing lens and a planar light source having the diffusing lens to increase light uniformity.
2. Description of Related Art
Light emitting diodes are used in displays as light sources. However, the light emitting diode is a point light source and has an excellent directionality while the display have a large-size screen and thus requires a large-size planar light source. As such, the light emitting diodes are arrayed and light emitted from each light emitting diode subjects to diffusion and homogenization by a diffusing lens having two concave surfaces. To efficiently diffuse and homogenize the light, curvatures of the concave surfaces should be sufficient large. However, it is difficult to mold a large-curvature concave surface.
Therefore, it is desirable to provide a diffusing lens and a planar light source, which can overcome the above-mentioned problems.